I've made a change to the OpenVR2Key program and now it will hold down the mouse click while the button is being held down on the controller. I'll attach the updated version.
Works great now. Had no problems using it in Blue Estate (which needs a continuous reload for the shotgun, probably one of the only games that do). It occasionally seemed to send a left click instead of a right click in M2 emulator, but I'm pretty sure that's an issue with the emulator or the game rather than OpenVR2Key, I've had similar issues before when trying to spam, and I can get similar behavior with a mouse by going too fast between left and right click. Still, got me through a full run of VC2 with very little issue, which is something I haven't been able to do in a while.
So it seems that Virtual Desktop will save the size and distance settings but when you start it again the rotation and position will be out depending on where the headset is in space.
The only thing I can think of at the moment would be to intercept the openvr_api.dll that is in the program folder and send a saved set of rotation/position co-ords to the virtual desktop exe when the program first starts up. And then it will need to resume normally after that.
I think it's possible but will take some time to work out. Also it will need for a position to be captured while setting it up that can be used to replay via dll as it will be specific to your lighthouse setup / monitor position.
Yeah, seems like a pain. I find recalibrating VD to not take that long, 2 or 3 attempts get it close enough across most of the screen. Setting up the screen dimensions is the fiddly part, and at least that saves. In my mind the way to do it would be to have something like OpenVR Input Emulator fix the headset position in space to a preset location (with maybe fine adjustment to dial in calibration), click the recenter button on the program to set the screen angle and spacing, and then cancel the headset position so it goes back to the actual one. I imagine if you did it while wearing the headset you'd want to throw up, though.
By the way, I also found while searching there is another virtual desktop type app called Desktop+ , it's free on Steam and is also on github with source code.
But I think maybe it's not going to be as good as VD.
I gave it a try and the tracking latency seems halfway between VM and VD, but the problem with it is that when the headset goes to sleep after 20 seconds it stops letting a controller act as a mouse, so it's no good. I think it also interferes with OpenVR2Key because it's part of the dashboard and OVR2K is blocked there (although I think older builds didn't have this functionality).
I've also noticed that when a tracker is set up as a controller, the pin for the touchpad button doesn't seem to do anything. Which means I've got to use the menu button instead, which is another point against vive mouse because it uses that input to disable the cursor. Not a huge number of games need more than 2 buttons, but it's a point of consideration.